1. Field of the Invention
The present invention relates to a wood-milling cutter, and more particularly, to a cutter which has simple configuration, whose height is conveniently and precisely adjustable and which is stably fastened.
2. Description of the Prior Art
A conventional milling cutter, as disclosed in TW Pat. No. 165938, is named as high-rigidity and light-weight milling cutter which primarily includes a cutter head and an engaging cutter seat. The cutter head is provided with a step-shaped through hole used to fasten the main shaft of the milling machine. The engaging cutter seat includes a cutter-receiving seat to lock and fix the cutter. The cutter head has a plurality of receiving grooves around the rim thereof into which the engaging cutter seats are inserted. The receiving grooves have trimming screw holes, fixing screw holes and positioning screw holes radially extended in the center and axially arranged. And the engaging cutter seat has a longitudinally and radially through hole in elongated oval shape through which a fixing screw is inserted to be screwed in the fixing screw hole. A circular through hole corresponding to the trimming screw hole is provided above the elongated through hole. A trimming indentation is arranged opposite to the through hole of the engaging cutter seat. An elongated oval blind hole is disposed in the longitudinal direction under the elongated through hole and lies opposite to the positioning screw hole. The thread member of the trimming screw is movable in the trimming screw hole of the cutter head. Meanwhile, a locating pin is provided at the other end of the thread member. The locating pin is placed within a positioning guide hole in position. The locating pin is extended at an eccentric position with a receiving head which is received within the trimming groove of the locating cutter seat. A positioning screw is screwed in the positioning screw hole and has a receiving head with a precise size. The receiving head is partially received within the positioning guide hole and partially extends outside the positioning guide hole. In addition, The receiving head is inserted into the elongated blind hole of the engaging cutter seat, thereby achieving the trimming and positioning effect of the engaging cutter seat.
Based upon the above-mentioned structure, the receiving head in eccentric connection will be deviated from the center when the locating pin is rotated. Thereafter, the engaging cutter seat is brought into motion. Moreover, the engaging cutter seat achieves a vertical adjustment by means that the elongated blind hole joins the receiving head of the locating pin to form a guide effect. However, this kind of structure has following disadvantages:
1. The travel of vertical adjustment depends on the eccentric connection distance between the receiving head and the locating pin. Therefore, the adjustment rang is very slight and doesn""t meet the requirement.
2. In assembling the engaging cutter seat, it""s required that the trimming screw and the locating pin are screwed into the cutter head first. Thereafter the trimming groove of the engaging cutter seat and the elongated blind hole correspondingly join the receiving head of the trimming screw and the outside of the locating pin. Thus, the assembly is very impractical.
3. The fixing of the engaging cutter seat completely depends upon that fixing screw is plugged into the elongated through hole. However, a great vibration and action force will be created, when the cutter head is rotated and cuts workpieces. As a result, the fixing effect only provided by a fixing screw will be easily lost.
It is a primary object of the present invention to eliminate the aforementioned drawbacks and to provide a wood-milling cutter in which a circular cutter head includes a plurality of semicircular engaging grooves at the rim thereof for receiving a plurality of hilts with corresponding arched surface. A semicircular screw hole is formed in the middle of the top rim of the semicircular engaging grooves. A blade is received at the bottom of said hilt. A semicircular cavity corresponding to the semicircular screw hole of the cutter head is provided in the middle of the top of the hilt and equipped with an annular flange. Therefore, the semicircular screw hole and the semicircular cavity form a full circular hole to receive a trimming screw with an annular groove in the middle thereof. The annular flange of the semicircular cavity is engaged in the annular groove of the trimming screw while the threaded member of the trimming screw joins the semicircular screw hole of the semicircular engaging grooves. The engaged position of the threaded member in the semicircular screw hole is changeable by tightening or loosening the trimming screw. Accordingly, the position of the blade is vertically adjustable. It is another object of the present invention to provide a wood-milling cutter in which a plurality of fixing screws can be driven through the hilt into the semicircular engaging groove of the cutter head so that the blade can be screwed in position.